New WSM Jet Pumps - Vanes broken and destroyed

[jason8887]

I just inherited a 96 Speedster from my brother who installed brand new WSM jet pumps with new impellers. I had it on the lake 3 times so far. The first two times I was experiencing a lot of ventilation/cavitation when trying to get on plane. before my last outing I did the zip-tie carbon seal boot trick and it made a big improvement when I first got on the water. After about 30 minutes of playing around the boat started producing almost zero thrust above 2500 rpm. We limped it back to shore and headed home. Today I started investigating the problem and I discovered that one of the jet pumps had every one of the rigid vanes broken and the impeller was flopping around in the wear ring. The other jet pump was on it's way to an early death with multiple vanes cracked and some with holes.

The impellers look like they are completely fine, with no nicks or damage on the blade edges or faces so I don't think I sucked up rocks. Any idea what could have caused this? Could the ventilation/cavitation that I was experiencing on my first two runs cause this kind of damage?

 

[wernerml]

In general cavitation causes pitting and erosion type damage. But it would also cause uneven pressures and vibrations. No telling what might happen with severe cavitation. Without you mentioning cavitation my first guess would have been out of balance causing vibration. Not sure how that would happen though.

I have had trouble with cavitation and replaced my seal last year. I was missing the C ring. It never resulted in any damage to the pump though. Runs good now.

 

[mikidymac]

Never seen that before.

Are the bearings still smooth and free?

Only other thing is if trash went through the pumps.

 

[pug pug]

Hiya all. For a little bit more money should have got the seadoo pump.the thing is they mite look the same but are definitely not. That’s why you pay the extra bucks. That WSM. Is ok if you want to buy in the cheep but for major components like pumps carbon seals bearings all the critical stuff stick with proper seadoo stuff. You all know the famous saying. Buy cheep by twice.!!. Be warned.!!!!!!!!.